Among the seven speech levels (levels of politeness) in Korean two are the most popular.

해요체 (haeyoche)

Haeyoche is the informal polite speech level, the most popular one in Korean, spoken most often in Seoul and largely throughout South Korea.

Korean words inflected in this speech level are characterized by the ending -요 (-yo) which you have already seen in previous lessons in words like 있어요 (iss-eo-yo) and 아니에요 (a-ni-e-yo).

하십시오체 (hasipsioche)

Hasipsioche is the formal, polite speech level, also often used in Korea.